Research

The goal of my research is to understand genetic and ecological factors that influence the rate of adaptive evolution in natural plant populations. I use the tools of quantitative genetics to explore the underlying genetic architecture of populations and to elucidate patterns of natural selection. One genetic attribute of plants that may strongly influence evolutionary rates but has received little attention thus far is polyploidy, the multiplication of chromosome number, which commonly occurs in many plant taxa. It is often assumed that polyploids possess greater evolutionary potential than their diploid progenitors because: 1) organisms with many gene copies harbor greater genetic diversity which is the fundamental substrate of evolutionary change, 2) genetic redundancy creates opportunities for duplicated genes to diverge and acquire new functions without compromising the original function, and 3) gene duplication increases the number of gene interactions, some combinations of which may enhance fitness. Thus, polyploidy may allow organisms to evolve faster or in novel directions compared to their diploid progenitors. In my current research, I am directly testing this hypothesis by conducting artificial selection for drought tolerance in experimental populations of diploids and higher ploidy levels. Students in my lab are exploring various aspects of this issue including the geographic distribution of different ploidy levels and the extent of their local adaptation to climate. Other students in my lab have examined different ecological genetic questions including the impact on native populations of invasive species and genotypes using both quantitative and molecular approaches.

Galloway, L.F. and J.R. Etterson. 2007. Inbreeding depression in an autotetraploid herb: a three cohort field study. New Phytologist 173:383-372.

Etterson, M.A., J.R. Etterson, and F. Cuthbert. 2007. A robust new method for analyzing community change and an example using 86 years of avian response to forest succession. Biological Conservation 138:381-389.